The Device And Achieve Of Screw Compressor Computer Control

The object of study of this thesis is an applied research of PLC control system of screw refrigeration compressor. This system consists of three subsystems including electric control, PLC programmable control and computer monitoring. This thesis deals with the principle of spindle compressor, the types of controller and control principle. It emphasizes not only PLC control and monitoring systems, but linear processing and its connection of PT100sensor as well. By using PLC of S7-200 series made by Siemens in German and STEP7 programmable software, the combination compressors can fulfill switching on and off, adjusted control, fault detect protect automatically. Meanwhile by using WinCC industrial process control also made by Siemens, this system has the functional pictures of real time temperature display and trend simulation, history record inquiry, alarm display as well as printing of report forms.